Photographic plate or film.



PATENTEDJAN( s1, 1905.

No. 781,469.y

J; H. SMITH; PHoToGRAPHIu .PLATE 0R FILM.

APPLIUATION FILIH) SEPT. 13.51904.

v Wre/4936.5

Patented January 31, 1905.`

PATENT l OFFICE.

JOHN HENRY SMITH, OF ZURICH, SWITZERLAND.

PHoToGRAPl-ilo PLATE on FILM.

SPECIFICATION formingvpart of Letters Patent No. 781,469, dated January 31, 1905.

Application filed September 13, 1904. Serial No. 224,312.

To all whom t may concern.-

Beit known that' I, JOHN HENRY SMITH, a subject of the King of Great Britain, residing in Zurich, in the Cantonof Zurich, Republic of Switzerland, (whose post-office address is No. 417 Seestrasse, Zurich,) haveinvented certain new and useful Improvements in Photographic Plates or Films; and'I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

I have applied for patent in Germany on September 17', 1903.

The combination of two photographic plates laid face to face in the camera for 'the purpose of obtaining in one exposure two negatives suitable for the preparation of two-color photographs is described in Gurtners German Patent No. 146,150, of July 1, 1902. The subject 'of my'Swiss Patent No. 29,446, of August 26, 1903` is a compound plate consisting of two photographic plates placed face to face with a thin transparentl sensitive film inserted between them for the purpose of obtaining in one exposure three negatives suitable for v.the production of three-color photographs. Both of these inventions are of practical application, althoughnot free from certain disadvantages. If two glass plates are employed, which is the simplest construction, it is necessary in order to have .sharp vnegatives to use expensive plate-glass, as

otherwise, and particularly with large sizes, there would be no certain ty that the surfaces would he in contact throughout. Should blemishes, such as small air-bells or impurities, occur at the back of the front plate, these will rbe transmitted to the first negative, because I coated in order to allow of the subsequent separation of the sensitive films.

Plates with several superposed sensitive surfaces coated upon them are not in themselves new, sueh plates having been employed for the prevention of halation during exposure. The sensitive surfaces were, however, in that case directly superposed without the introduction of a separating medium, .as a subsequent separation of the sensitive films was never intended.

. The accompanying drawings show two examples of the subject of this invention as applied to three-color photography and employing gelatin dry-plates. V

In Figure I, a is the glass su pport, b the first, b2 the second, and b3 the third, sensitive surface, obtained by coating three gelatineargentic emulsions of suitable color sensitivevness and general sensitiveness. Between b and b2, aswell as between 792 and b3, a neutral transparent collodion film c and c2 is coated. I f necessary, the separating neutral films may be colored in order to act as light-filters to the underlying sensitive films.

In the modication shown in Fig. II the glass plate c is the support for the two sensitive films b/ and b2, brought into intimate combination by the transparent neutral film c, while the third sensitive rfilm b3, supported uponl a glass plate CZ as an ordinary dry-plate,

is placed upon the middle film and kept loosely in contact with the compound plate by external means-e. g., a binding-strip of paper c.

After the exposure has beenl made the upper sensitive films 'are separated and transferred to an adhesive surface--a g., a glass platewith a gelatin surface-upon which case the substratum should be omitted. Ink

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order to separate the upper sensitive films pound photographicplate or film consisting` when the support is a glass plate, it is advisable to employ a fieXible non-expanding cloth or paper, 850., coated with a suitable adhesive material. After the compound film has been cut through along the edg'es the adhesive cloth is squeegeed onto the surface of the plate, a corner of the upper sensitive filn'i lifted with a penknife, and the film carefully stripped off the plate. The film is then squeegeed onto its permanent support--eg., a glass plate with a moist gelatin surfaceand allowed to dry, with the adhesive cloth still in contact. After drying the adhesive cloth is easily stripped ofi,the sensitive film forming with the gelatin surface of the plate an intimate combination, enabling' the plate to pass through all the ordinary photographic baths without the slightest expansion or frilling. The remaining sensitive films, with the exception of the last one, together with their overlying eollodion or celluloid films, are stripped off by means of the adhesive cloth and squeegeed direct onto the gelatin surface of the glass plate. After drying and removal of the adhesive cloth the overlying eollodion film is removed by dissolving in a suitable solutione. g., methyl alcohol-in order to allow of the subsequent development of the plate. The last sensitive film need not be removed from its support as long as the latter consists of a transparent material; but the overlying collodion film should be removed in the manner described before developing. Should the common support consist of paper or other opaque substance, the last sensitive film may be transferred to a permanent transparent support in the same manner as described if the paper receives a coating of gelatin, followed by a coating of eollodion, before the sensitive films are superposed to assist the transference. If desired, the upper sensitive film after being lifted from the plate may be squeegeed to a second adhesive cloth before transferring to its permanent support in order to reverse the negative.

That I claim isl. As a new article of manufacture a compound photographic plate or film consisting of a single support upon which are coated two or more layers of sensitive photographie material, each two adjoining layers being sep- 'arated by a coating of neutral transparent material for the purpose of subsequently separating the sensitive layers.

2. As a new article of manufacture a coniof a single support upon which are coated two or more layers of sensitive photographic material, each two adjoining layers being sep-- arated by a coating of neutral transparent niaterial for the purpose of subsequently se parating the sensitive layers, in combination with an ordinary single-filni photographic plate or film placed face to face and loosely bound together substantially as described.

3. As a new article of manufacture a conipound photographic plate or film consisting of a single su pport upon which are coated two or more layers of sensitive photographie niaterial, each two adjoining layers heilig separated by a coating of neutral transparent niaterial for the purpose of subsequently separating the sensitive layers, one or more of the neutral separating layers being colored in order to act as color-filter to the underlying sensitive layer or layers, substantially as described.

4. As a new article of manufacture a compound photographic plate or film consisting of a single support upon which are coated two or more layers of gelatino-argcntic emulsion, each two adjoining layers being separated by a coating of eollodion or celluloid for the purpose of subsequently separating the emulsion layers, substantially as described.

5. As a new article of' manufacture a compound photographic plate or film consisting of a single support upon which are coated three layers of sensitive gelatino-argentic emulsion each two adjoining layers being' separated by a coating of celluloid orcollodioii for the purpose of subsequently separating the sensitive layers, the sensitive layers being so adjusted in respect of general and color sensitiveness and the adjustment assisted if necessary by tlie coloration of the eollodion films so that upon correctly exposing the compound plate upon a suitable subject, separating the sensitive layers as described, and developing them upon their new supports three negati ves are obtained suitable for the production of three-colored photographs, substantially as described.

ln testimony whereof l have signed n1 y name to this specification in the presence of two subscribing witnesses.

VitneSSes:

HnniiANN HUBER, Josnru SIMON.

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